So I am aware of the Clausius inequality which states the following:
- ∮δQ/T≤0 around a cycle.
Now consider the following question:
Consider a real heat pump which in one cycle extracts heat Qc from the ground at temperature Tc and delivers heat Qh to a building at at temperature Th. Use the Clausius inequality to show that Qc < QhTc /Th.
- The solution to this answer is as follows:
Using the Clausius inequality:
Qc/Tc - Qh/Th < 0 --> Qc < QhTc /Th
My question is how did we know that Qc/Tc - Qh/Th < 0
as opposed to Qh/Th - Qc/Tc <0 which would obviously yield a different result.